Circuit interrupter



Dec. 29,A 1931. J. N. MAHONEY' 1,339,107

. CIRCUIT INTERRUPTER Filed .inn-2'?, 1925 Patented Dec. 29, 1931v j A UNrreusi-ATES PATENTJOFFICE Josera N. xAHoNEY, on BaooxLYN, NEW Yonx', nssreNon, mr-xnsNnnssreNnmTs,

. To coNnrT ELEcTnIcAL MANUFAGTUBING conronATIoN, or BosToN, unssncnusETTs, A CORPORATION 0F MASSACHUSETTS l y A CIRCUIT INTERBUPTEB .Y

nppuatian minnen, i935. 'semi No. 0.030.` v

This invention relates to electric circuit interrupters and has for an object the provision 'of means to introduce an impedance into the circuit during circuit interruption whereby to reduce the amount of energy to be interru ted.

A' urther object of the invention is generally to improve vthe construction and operation of circuit injterrupters.`

The broad idea of rotating the circuit interrupting larc is -disclosed in the cor-pending vapplications of Talma T.` Greenwood, Serial No. 755,353, filed December 11, 1924; and Serial No. 33,848, led May 29, 1925 and assigned to the assignee'ofthls application.

Fig.1 is a sectional detail illustrating the stationaryand movablel members of the cir-j cuit interrupter inthe closed position thereof. Fig."2 isa view similar to Fig..1but with the impedance introduced into 4the circuitv and prior to complete circuit interruption. y

Fig. 3 is a view similar to Fig. 2 but illus# trating the complete openl circuit position of the circuit interrupting members.

Fig. 4 is a sectional elevation'illustrating a modified formof theinvention. Y. 5 is a view similar to Figl4 but illustrating the rrelation of the parts vin ,opencircuit position. e. f Y i l Fig. `6 is a kmodified form of the structure illustrated inFig. 1 wherein the impedance is arranged to short-circuit itselfy in the closed condition of the interrupter.

In the construction illustrated 4in 1 2 and 3, lthe circuit interrupter includes a stationary switchv terminal including an insulator 410 which ysurrounds a conducting stud 12. 'A plate 14` is electrically` and mechanically connected with the lower end .of said'switch stud( A housing 16 is secured fixedly and preferably removabl `to the lower face of said plate 14 b suitev lemeans as by the bolts y18. A multi-part fixed contact member 20 is disposed within said housing and the `parts thereof are held yieldjngly in contracted position by suitablelneans vas the encircling coil 4spring 22. o

In accordance with this invention, an impedance memberiis associated with .the interrupter and is adapted tobe included in the Vinaddition to having circuit through the interrupter at the period of circuit interruption whereby to choke down the amount of energyto be finally interrupt? ed atV the'circuit-interru tingarc. As here shown, the impedanceis elical in form and comprises a plurality lof'V convolutions 24 which ma `normally assume'aymore yor less cylindrica form. Said .impedance member may becomposed of any suitable resistance material, as,` for instance, spring steel and, resistance, also has re.- Vactance by virtue o its convolutions. The resilient convolutions, inthe closed Acondition of the interruptor, are adaptedfto be disposed in closed order, or in actual mechanical and electrical contact, as indicated-in Fig. 1 but when the interrupter is operatedrto nterrupt the circuit, said convolutions are adpted to open up as illustrated in Figs. 2 an '3. j i 4Said impedance element preferably is` coaxially disposedy with "the passa e through the stationary contact member go, and depends therebelow. An u per convolution 24 thereof maybe retaine `in springfpressed engagement in egreeve ef en annuler flange 26 of the housing .16y whereby to support the impedance in the laforesaid relation. In the closed condition of the interrupter, said impedance member is ada ted normally t0 be short circuited and there y cutout of the circuit through the interruptor. ,To this end one ofthe 'lower convolutions of the impedance member is secured to an annulaflange 28 cfa secondary or intermediatemovable contact member 29 which also constitutes a circuit-interrupting arc'r, V which has a stem BOeXtende A upwardlyin position to enter and engagethe tired contact member v20. Said stem 30 is hollow and is adapted to receive .thev movable circuit-interru ting arcing k'member 32 of the interruptor, llnthe normally closed condition of the interruptor, the impedance Vmember is short vcircuited by the engagement of `the secondaryfcontact member 29 with the fixed contact member the current traverses the switch throu r`l1 said two contact members and the movab e con- ,tact member 32 and excludes the impedance.

When the circuit interruptor is operated to M0 =member, and f interrupt the circuit, the movable contact member is lowered. Due to the resiliency of the impedance member, the secondary contact member is maintained in position on the upper end of and in contact with the movable circuit-interrupting arcing member and is thereby withdrawn from the fixed Contact member Q0, thereby introducing the impedance member actively in the circuit. At the moment of separation of the iixed and secondary contact members an arc may take place and the extent of separation of said members is adapted to be suflicient to cause the extinguishing of the are. A continued downward movement oi' the movable circuit interrupting member eli'ects its separation from its cooperating circuit-interrupting member 29 and a circuit-interrupting arc may be drawn between said two members. The arc will be extinguished by reason of its attenuation and the cooling eilect of the bath of oil or other arc quenching fluid in which the Contact members may be immersed.

Under certain circumstances, it may not be necessary to provide short-circuit contact members for the impedance member. In the construction illustrated in F ig. 6, for instance, when the circuit interrupter is closed, the convolutions of the impedance member are adapted to be pressed forcibly into electrical contact with each other, so that the convolutions short circuit themselves.

In the modiiications illustrated in Figs. 4 and 5, the convolutions 24a of the impedance member are arrangedin concentric and approximately flat form in the closed position of the interruptor and each convolution is arranged to be in independent Contact with the lower face of the housing 20a. As thus arranged, during the opening movement of the interrupter, the convolutions separate in progressive order from said housing and thereby gradually and progressively introduce the impedance into the circuit.

The resilient impedance member also serves as a spring to speed-up the opening movement of the movable circuit-interrupting arcine member.

laid impedance member also acts as a solenoid to eifect the rotation oi the circuit interrupting arc between the circuit-interrupt ing arcing members whereby to enhance the speed of circuit interruption.

The helical spring provides for a universal movement of the contact member carried by it, by which the contact member can align itself with its cooperating contact member, when one is moved into the other.

The construction may be otherwise modified without departing from the spirit of the invention.

I claim l. A circuit interrupterlcomprising separable contact members, separable arcing members affording an endless path for an arc draw therebetween, and means for inserting currentlimiting impedance between said contact members when the latter are separated and for providing an arc-rotating field torotate the arc drawn between said arcing members.

2. Means for interrupting an electric circuit comprising a current-limi ting impedance which also provides an arc-rotating ield, a pair of arcing members in said circuit, and means for separating said arcing members to establish an arc therebetween in such relation to the field of said impedance that the arc is rotated thereby.

3. An electric circuit interrupter including an interrupter terminal having a fixed anuular contact, a flexible helicoidal current- 1iimiting impedance having its upper end supported by and electrically connected with said terminal, said current-limiting impedance also providing an arc-rotating lield, an annular circuit-interrupting arcing member carried by and electrically connected with the lower end of said helicoidal impedance and adapted to engage within said annular contact, and a movable Circuit-interrupting arcing member to control the circuit through said impedance and also through the interrupter engageable within said annular circuit-interrupting arcing member, said arcing members al'lording an endless path for the arc drawn therebetween whereby the are can be rotated by the field of said impedance.

4f. An electric circuit interrupter including an interrupter terminal, a iexible helicoidal current-limiting impedance having its upper end supported by and electrically connected with said terminal, said current-limiting impedance also providing an arc-rotating field, an annular circuit-interrupting arcing member carried by and electrically connected with the lower end of said helicoidal impedance, and a movable circuit-interrupting arcing member to control the circuit through said impedance and also through the inter rupter engageable within said annular circuit-interrupting arcing membersaid arcing members affording an endless path for the arc drawn therebetween whereby the arc can be rotated by the lield of said impedance.

5. An electric circuit interrupter including an interrupter terminal, a lexible helicoidal current-limiting impedance having one end thereof electrically connected to said ter minal, a circuit interrupting arcing member electrically connected to the other end of said helicoidal impedance comprising a hollow stem concentric with said impedance and having a flaring opening, and a movable circuit interrupting arcing member within said hollow stem and movable through said iared opening to interrupt the circuit, said arcing members having such an arrangement with respect to each other and to said impedance that the arc drawn between said engageable l arcing members is traversed by the eld of said impedance and rotated thereby. ,i

6. An electric circuit interrupter including a member having the combined properties of a current-limiting impedance and a' rotator for the circuit interrupting arc, a fixed con-V tact member and circuit-interrupting arcing members, affording an endless path for the arc, one of said circuit interrupting arcing members engageable with said fixed Contact member and With the other arcing member, said arcingmembers having their arcing surfaces so arranged with respect to each other and said impedance that the are drawn bej tween them is traversed by the field of said impedance and rotated thereby.

7 An electric circuit interrupter including a member having the combined properties of a current-limiting impedance and a rotator for the circuit ntcrruptingarc, and cooperating arcing members affording an endless path for the arc engageable with and disengageable from each other to close and open the circuit and constructed and arranged so that the arc drawn between them is traversed by the eld of said impedance and rotated thereby.

In testimony whereof, I have signed my name to this specification.

JOSEPH N. MAHONEY. 

